Catalysts to Convert Carbon Dioxide

Lawrence Livermore researchers have received $1 million from the Department of Energy (DOE) to improve the energy efficiency of copper-based catalysts to convert carbon dioxide (CO2) into methane and other valuable hydrocarbon products. Led by Livermore’s Juergen Biener, the project will help meet the nation’s future energy needs by converting low-cost, abundant resources into commercially viable fuels. Catalysts play a key role in such efforts, converting CO2—an industrial waste product—into methane, a versatile fuel that can be readily integrated into efforts to fuel vehicles and power plants. Catalysts can also convert excess electrical energy produced by renewable energy resources, such as solar and wind, into chemical energy, making it easy to store the energy for future use.

However, current electrochemical catalyst technologies are energy intensive and costly and therefore unlikely to be competitive with traditional fuel production methods. The new work is aimed at overcoming the limitations of current approaches that use catalysts to convert CO2 into fuels.

To optimize the catalysts’ performance, the team will fully integrate the Laboratory’s unique expertise in the synthesis and characterization of nanostructured dilute alloy transition metal catalysts with atomically precise active sites, along with the multiscale modeling of electrochemical interfaces. This project was funded by the DOE Advanced Manufacturing Office to support early-stage, innovative technologies and solutions in advanced manufacturing.
Contact: Juergen Biener (925) 422-9081 (biener2@llnl.gov).

Scientists Design Conceptual Asteroid Deflector

Livermore scientists are part of a national planetary defense team that designed a conceptual spacecraft to deflect Earthbound asteroids and evaluated whether the craft could nudge off course a massive asteroid that has a remote chance of hitting Earth in 2135. The design and case study are outlined in the February 2018 edition of Acta Astronautica.

Dubbed HAMMER (Hypervelocity Asteroid Mitigation Mission for Emergency Response Vehicle), the spacecraft can serve as either a kinetic battering ram or as a transport vehicle for a nuclear device. The possible target is 101955 Bennu, which has a 1-in-2,700 chance of striking Earth on September 25, 2135.

The design effort is part of a national planetary defense collaboration between NASA and the National Nuclear Security Administration (NNSA). The Livermore planetary defense team serves as technical lead for threat mitigation and also supports emergency response should mitigation fail. Unlike popular portrayals such as the movie Armageddon, the nuclear deflection approach would involve detonating a nuclear explosive some distance from the asteroid. The explosion would vaporize a layer of the surface, thereby generating rocketlike propulsion as material is ejected from the asteroid.

Because Bennu passes close enough to Earth every six years, researchers are able to estimate its orbit with enough accuracy to give a few decades’ warning. However, for other objects that do not regularly pass close enough to Earth for radar observations, much more uncertainty exists. The good news is that most of these objects are much smaller than Bennu.
Contact: Megan Bruck Syal (925) 423-0435 (syal1@llnl.gov).

Optimizing Nanoparticles for in vivo Applications

Lawrence Livermore has been developing a novel class of nanoparticles (see image below) for biomedical applications that are highly biocompatible and offer advantages not found in other types of nanoparticles. Termed nanolipoprotein particles (NLPs), the nanoparticles are laboratory-made versions of high-density lipoproteins—or “good cholesterol”—that are used by the body to transport triglycerides and remove harmful “bad cholesterol” in the blood.

The Livermore team recently assessed how the structure of phospholipids used to prepare the particles impacts their stability under physiologically relevant conditions. This key information has important implications for using these NLPs in vivo and would provide insight into how to tune particle stability for applications ranging from diagnostics to drug delivery. The findings appear in the April 28, 2018, edition of Nanoscale. The research was supported by the Laboratory Directed Research and Development Program.

Nanoparticles are nanoscale objects, typically 1 to 100 nanometers in size, that can be used for a variety of purposes, including formulating medicines or vaccines. As of 2016, 51 nanoparticle drugs had already been approved by the U.S. Food and Drug Administration to treat a range of diseases, with another 77 candidates in clinical trials.

Although preliminary studies had previously demonstrated that the type of phospholipid used to synthesize these particles can affect their stability, how specific phospholipid features impact nanoparticle stability under physiologically relevant conditions was previously unclear. Livermore’s results demonstrated that the elasticity of the lipid bilayer—but not lipid surface area or thickness—is a significant indicator of particle instability in the body. These studies provide a foundation for subsequent optimization of NLP composition to tailor stability for the particular in vivo application.
Contact: Nicholas Fischer (925) 422-6144 (fischer29@llnl.gov).